Well I am back from the doctor. He said I probably have a slight tear in the ACL. So he gave me 2 options, get a cortizone shot or get an MRI. He told me he chose the MRI because he doesn't like needles, but also said after an MRI the cortizone shot is still an option. So I opted to take the shot and have fluid removed from my knee. He said it was good that the fluid was yellow, and I got stabbed twice by a 4" needle because he didn't like the first needle, maybe not long enough I guess. So anyhow, the second needle didn't hurt as bad and he ended up pulling out 17 ml of yellow fluid. He said if it was red that would have been a bad sign.